Monitoring system and method for the in-process monitoring of machine-tool components

ABSTRACT

In a monitoring system for the process-accompanying monitoring of machine tool components, it is provided that the same monitoring system, apart from the detection of at least one of the above mentioned conditions in tools, workpieces or processes, is used in other monitoring stages—which at times when no treatment process occurs (i.e. when no tool, workpiece or process monitoring has to occur) are predetermined by the machine control—to perform a detection, monitoring or well-aimed examination of faulty conditions on components of machine tools, such as e.g. damage or wear on the feed slides, on the tool or workpiece spindles or the imbalance on tool or workpiece spindles or on drilling or milling tools.

BACKGROUND OF THE INVENTION

The invention relates to a monitoring system as well as to a methodinvolving a monitoring system for standard use in theprocess-accompanying monitoring of tools, workpieces or treatmentprocesses in machine tools of the cutting type.

Those components of machine tools which are subject to wear or which aresusceptible to damage due to machine collisions, machine overstressingor imbalanced tools or workpieces, are in need of monitoring. Suchmachine components are substantially those which carry out movements inthe machine tools. Therefore, they are substantially restricted to feedslides, tool and workpiece spindles but also include aggregates for thefurther operation of a machine tool of the cutting type.

Provided that a monitoring system for the process-accompanyingmonitoring of tools, workpieces or treatment processes has beeninstalled, the method of the invention makes it possible, in performingthe monitoring or checking of feed slides and tool and workpiecespindles, to obviate the need for separate monitoring devices, resultingin a considerable potential for cost reduction because the hardware, thesoftware, the operating means and the interface for machine control neednot be provided twice.

There exist several known monitoring devices for the monitoring ofvibrations on rotating machines and machine components. These areprimarily useful for the detection of vibrations and imbalances inengines and transmissions and partially also for the detection ofimbalances in machine tool spindles. Some of these devices are alsoadapted to detect damage on bearings by means of vibration measurements(e.g. the Vibration Monitor VIMO 100 of PROMETEC GmbH, Aachen, cf.enclosure “Vibration Monitor VIMO 100”, Prometec company, Aachen, and“Modulares Prozess Monitor System PROMOS”, Prometec company, Aachen).The contents of these printed publications are herewith incorporated byreference into the present disclosure.

Further, it is known that machine tools can be provided with vibrationdetectors arranged on the spindle housings near the bearings to thusdetect damage to the bearings, and that the cables of the sensors can beguided to accessible plugs on the front of the machine tool. From timeto time, the maintenance personal will use these plugs to analyze thesignals for bearing damage by means of analyzing devices. For thispurpose, the signals are recorded by analyzing devices and will beanalyzed off-line at a later time. An in-process monitoring is notperformed here.

Monitoring systems for the process-accompanying monitoring of tools,workpieces or treatment processes in cutting-type machine tools forrotating, drilling or milling serve the purpose of in-process detectionof at least one of the conditions of tool breakage, tool breakout, toolwear, contact between tool and workpiece, rattling or machine collisionand—particularly in case of tool breakage or machine collision—shallbring the machine drives to a standstill as quickly as possible topreclude consequential damage.

Such in-process monitoring systems are already provided with an electricinterface between the monitoring system and the machine control means soas to perform an in-process monitoring of the signal developments of thesensors at monitoring intervals which are predetermined by the machinecontrol means and, in case of a detection of any one of the abovementioned conditions, to bring the machine to a standstill through thesame interface. The interfaces between the machine tool control meansand the monitoring system have up to now existed substantially in theform of parallel input and output signals for SPC control. Such aparallel interface between the SPC and a tool and process monitoringsystem can be designed e.g. in accordance with the BAPSI standard whichalso already allows for the transmission of data words as tool codes orcutting codes from the NC program to the monitoring system. Onlyrecently, manufacturers of control devices increasingly offer field businterfaces in addition to or instead of these parallel interfaces; thefield bus interfaces make it possible to perform a wider exchange ofinformation between the machine control means comprising the storedprogram control (SPC) or the NC control.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a monitoring system and amethod for the process-accompanying monitoring of machine toolcomponents which are adapted, without the need for significant changesin the hardware or software of the monitoring system, to monitor orcheck components of machine tools.

According to the invention, the object—for fusion a monitoring systemfor the process-accompanying monitoring of tools, workpieces ortreatment processes in cutting-type machine tools for rotating, drillingor milling for at least the conditions of tool breakage, tool breakout,tool wear, tool-workpiece contact and rattling, with a workpiececomponent monitoring system for the detection, monitoring or checking offaulty conditions in components of machine tools, such as damage or wearon feed slides or on the tool or workpiece spindles, or imbalance oftool or workpiece spindles or of drilling or milling tools—is achievedin that both objects are realized with the same monitoring hardwareincluding corresponding evaluation software and with the samebidirectional interface, preferably a field bus interface, between themonitoring hardware and the machine control means.

Use is made merely of additional sensors on the machine tool components,the feed slides or the tool or workpiece spindles, if such sensors werenot required for the original process-accompanying monitoring task to beperformed on tools, workpieces or treatment processes.

The systems for the in-process bearing monitoring or vibration orimbalance monitoring are, apart from a tool or process monitoringsystem, additionally connected to the same field bus. A correspondingmonitoring system for the monitoring of spindle or bearing imbalancewhich includes a serial interface, has been previously unknown.

Presently, monitoring systems for the process-accompanying monitoring oftools, workpieces or treatment processes in cutting-type machine toolsfor rotating, drilling or milling are provided, in the sense of standardfeatures, with all kinds of monitoring thresholds and monitoring andevaluation strategies of any known and desired type, such as statisticalthresholds, dynamic thresholds, thresholds of signal pattern curves,operating value thresholds etc., just as these are also required for themonitoring of faulty conditions on components of machine tools.

The invention solves the problem residing in when and how the machinecontrol means, forming the controlling component for the monitoringstages for the detection of faulty conditions of components of machinetools, has to act, and whether or how it will move or shift or rotatethe feed slides or the tool or workpiece spindle, possibly forgenerating corresponding signals at the sensors of the machine toolcomponent.

The invention further provides a process-accompanying monitoring systemfor the monitoring of tools, workpieces or treatment processes incutting-type machine tools for rotating, drilling or milling, can alsobe used for the detection, monitoring or well-aimed examination offaulty conditions in components in machine tools.

Additional sensors can be provided on the components of machine tools towhich the monitoring system can be automatically switched in dependenceon the monitoring stage selected by the control.

BRIEF DESCRIPTION OF THE DRAWING

The single FIGURE of drawing illustrates the monitoring system of thepresent invention.

DETAILED DESCRIPTION OF THE INVENTION

A monitoring system 10 for the process-accompanying monitoring of tools,workpieces or treatment processes in machine tools of the cutting typefor rotating, drilling or milling, with the purpose of detecting atleast one of the conditions of tool breakage, tool breakout, tool wear,contact between tool and workpiece with or without workpiece gauging,machine collision or process abnormities such as rattling, or tool-,workpiece- or cut-specific overload or underload, is illustrated in thesingle FIGURE of drawing.

The monitoring system 10 comprises at least

-   -   one or a plurality of sensors 11, 12, 13 for the detection of        measurement signals 103 from the treatment process, which are        representative of at least a direction of force, a resultant        force, a pressure, a moment of rotation, an engine performance,        an engine current, a vibration, an acceleration, a        structure-born sound or a change of distance between two machine        components,    -   monitoring hardware with software, generally designated with        numeral 14, for the storing and comparing of monitoring data        104, 105 in tool- or cut-specific monitoring stages which are        preset by the machine control means 16 through the NC or/and SPC        program via an interface 15 and in which measurement signals 102        or measurement signal curves of at least one sensor 11, 12, 13        are compared with stored monitoring thresholds by means of        monitoring and evaluation strategies of a known and desired type        such as static thresholds, dynamic thresholds, thresholds of        signal pattern curves, operating value thresholds, etc. with the        purpose of providing, in case of measurement signals violating        the monitoring thresholds, a corresponding message to the        machine control means to thus initiate a corresponding reaction        of the machine,    -   a bidirectional interface 15, preferably a field bus interface        between the monitoring hardware 14 and the machine control means        16, comprising the SPC or/and the NC control means, which        performs a data exchange 104, 105 between the machine and the        monitoring system 14 and which particularly is suited to        transmit the tool- or cut-specific monitoring stages in the form        of data words as distinct numbers or instructions (e.g. as tool        codes, tool correction or position numbers, cutting code, H and        M instructions), from the NC or SPC program to the monitoring        system for dividing the monitoring into a plurality of        monitoring stages,    -   as well as, possibly optionally, operating hardware 17 for        operating and/or parametrizing the monitoring system and/or for        visualizing the measurement signals, whereby        -   the same monitoring system 10, apart from the detection of            at least one of the above mentioned conditions in tools,            workpieces or processes, is used in other monitoring stages,            which at times when no treatment process occurs (i.e. when            no tool, workpiece or process monitoring has to occur) are            predetermined by the machine control, to perform a            detection, monitoring or well-aimed examination of faulty            conditions on components of machine tools, such as e.g.            damage or wear on the feed slides, on the tool or workpiece            spindles or the imbalance on tool or workpiece spindles or            on drilling or milling tools.

Further according to the invention the monitoring system 10 cancomprise, for each monitoring task to be performed on components ofmachine tools, one or a plurality of additional sensors suited to thistask which automatically switch the monitoring system 10 when thecorresponding monitoring stage for the monitoring task to be performedon components of machine tools is called up by the machine control 16.

In the monitoring system 10 according to the invention for themonitoring of damage or wear on feed slides, said feed slides can beprovided with force sensors for detecting the feed force in the slidemoving direction on one of the feed spindle bearing blocks, or areprovided with current or performance sensors on the feed spindleengines, or, by reading the measurement values of the existing currentsensors on the feed drive means from the machine control means 16, viathe bidirectional interface 15, which is preferably designed as a fieldbus interface, or, for a possible monitoring of noises or vibrations onfeed slides, these are provided with one or a plurality of sensors forstructure-borne noise and/or vibration sensors arranged on the slides,the moving tracks or/and the spindle bearing blocks.

According to the invention in a method for the process-accompanyingmonitoring of machine tool components by use of the above describedmonitoring system 10 the machine control 16, during the period in whichit sets the monitoring system 10 to enter the monitoring state for themonitoring of feed slides, will also move the one or the plurality offeed slides across the moving regions to be monitored, preferably acrossthe complete moving regions without performing a treatment process atthis time, and the machine control 16 can carry out these movementsthrough an NC subprogram portion which is called up together with thedata word for the monitoring stage.

Further according to the invention in said method the machine control 16can perform the monitoring stage for the monitoring of feed slides whenno workpiece is arranged in the machine so that the complete movingregions can be moved or reciprocated without a danger of collision andwithout a treatment process.

According to the invention in said method particularly in the massproduction of workpieces, the machine control 16, for the monitoringstage for the monitoring of feed slides, can cause its feed slides toperform the normal NC program for treatment of this workpiece but willnot insert a workpiece into the machine for this purpose and in thiscase, instead of the monitoring stages for the monitoring of tools,workpieces or treatment processes, will transmit the monitoring stagefor the monitoring of feed slides to the monitoring system.

Further according to the invention in said method during the call-up ofthe monitoring stage, the movement of the feed slide can always beidentical and the monitoring cycle is repeatedly initiated by themachine control at regular time intervals and with identical operatingconditions.

In said method the monitoring stage for the well-aimed monitoring offeed slides can be preset by the machine control virtually for anunlimited number of times during the lifespan of the machine tool.

Further the distance in time between respectively two identicalmonitoring stages for the well-aimed monitoring of feed slides can bepreset by the machine control in accordance to the time when a justabout perceptible wear-induced change on the moving tracks would beexpected.

Further according to the invention in said method in new orunobjectionable, wear-free feed slides, a teach-in monitoring stage canbe performed in which the measurement signals 102 or measurement signalcurves of the sensors 11, 12, 13 are stored in the monitoring system 10and, in relation thereto, the switching thresholds or switchingthreshold curves for the maximum allowable deviations of the sensorsignals for the future monitoring stages are determined up to the end ofthe lifespan of the feed slides of the machine tool.

In said method the measurement signals 102 or measurement signal curvesof the sensors 11, 12, 13 from the sequential identical monitoringstages for the monitoring of the feed slides can be stored in themonitoring system 10 and be read out at all times.

Further according to the invention in said method after machinecollision or tool breakage, which the machine control can detect as amatter of a standard feature and which it will communicate to themachine control, the machine control 16, after elimination of thecollision or breakage situation, can first perform, at the start of theregular treatment in automatic operation, a—relatively to the otherwisecommon chronological order—unscheduled monitoring stage for thewell-aimed monitoring of the feed slides, and the monitoring system 10can in this case separately store the measurement signals or measurementsignal curves of the sensors in order to document possible damage causedby the collision or the tool breakage on the feed slides.

According to the invention in a second method for theprocess-accompanying monitoring of machine tool components by use of theabove described monitoring system 10, for the monitoring of damage orwear on tool or workpiece spindles, primarily on their bearings, as wellas for the examination of inadmissible imbalance on tool or workpiecespindles, said tool or workpiece spindles are provided with sensors forstructure-borne sound provided for the detection of the running noise,or with vibration sensors for the detection of spindle vibrations, orwith distance sensors for the detection of displacements between twospindle components, preferably between rotor and stator relative to eachother, or with temperature sensors for the detection ofpower-loss-induced increases in temperature, which are each arranged inthe immediate region of the bearings, or with current or performancesensors on the tool or workpiece engine, further, by reading out themeasurement values of the existing current sensors on the spindle drivemeans from the machine control 16, via the bidirectional interface,which is preferably provided as a field bus interface, for the detectionof power-loss-induced increases in current or performance.

According to the invention in said second method the machine control 16during the time in which it sets the monitoring system 10 to themonitoring stage for the monitoring of tool or workpiece spindles, cancontrol also the spindles into the rotational speed ranges to bemonitored, and preferably can increase and decrease their rotationthrough their whole rotational speed range without performing atreatment process at this time, and can perform the controlling of thespindles through an NC subprogram portion which is called up togetherwith the data word for the monitoring stage.

Further according to the invention in said second method the machinecontrol 16 can perform the monitoring stage for the monitoring of toolspindles when no tool is arranged in the machine so that the measurementsignals cannot be adulterated by the tool.

In said second method the machine control means 16 can perform themonitoring stage for the monitoring of workpiece spindles when no toolis arranged in the machine and the workpiece chuck is positionedidentically so that the measurement signals cannot be adulterated by theworkpiece or the workpiece chuck.

According to the invention in said second method during the calling-upof the respective monitoring stages for the monitoring of the tool orworkpiece spindles, the respective developments of the rotational speedsinclusive of the acceleration or deceleration phases can be alwaysidentical, and the respective monitoring cycles for the correspondingtool or workpiece spindles can be repeatedly initiated by the machinecontrol 16 with identical operating conditions of the machine tool.

In said second method the monitoring stages for the well-aimedmonitoring of tool or workpiece spindles can be preset by the machinecontrol virtually for an unlimited number of times during the lifespanof a machine tool.

Further the distance in time between respectively two identicalmonitoring stages for the well-aimed monitoring of feed slides can bepreset by the machine control in accordance to the time when a justabout perceptible wear-induced change on the moving tracks would beexpected.

According to the invention in said second method in new orunobjectionable, wear-free tool or workpiece spindles, respectively oneteach-in monitoring stage can be performed in which the measurementsignals 102 or measurement signal curves of the sensors 11, 12, 13 arestored in the monitoring system 10 and, in relation thereto, theswitching thresholds or switching threshold curves for the maximumallowable deviations of the sensor signals for the future monitoringstages can be determined up to the end of the lifespan of the tool orworkpiece spindles in the machine tool.

Further in said second method the measurement signals 102 or measurementsignal curves of the sensors 11, 12, 13 from the sequential identicalmonitoring stages for the monitoring of the tool or workpiece spindles,can be stored in the monitoring system 10 and be read out at all times.

According to the invention in said second method after machine collisionor tool breakage, which the machine control 16 can detect as a matter ofa standard feature and which it communicates to the machine control 16,the machine control 16, after elimination of the collision or breakagesituation, can first perform, at the start of the regular treatment inautomatic operation, a—relatively to the otherwise common chronologicalorder—unscheduled monitoring stage for the well-aimed monitoring of thetool or workpiece spindles, and the monitoring system 10 can in thiscase separately store the measurement signals 102 or measurement signalcurves of the sensors 11, 12, 13 in order to document possible damagecaused by the collision or the tool breakage on the tool or workpiecespindles.

In said second method particularly in the mass production of workpieces,the machine control 16, for checking the tool or workpiece spindles fordamage or wear, can perform the normal NC program for treatment of thisworkpiece but will transmit to the monitoring system 10, in addition tothe normal monitoring cycles for the monitoring of tools, workpieces ortreatment processes, a specific monitoring stage for checking the toolor workpiece spindles for damage or wear during the respectiveacceleration of the spindle to the respective desired rotational speedprior to the treatment process involving the respective tool orworkpiece, and in the process will check the measurement signals in theacceleration phase of the spindle preferably by expansion of signalpattern curves from a corresponding teach-in monitoring stage.

Further the corresponding checking can be performed during thedeceleration of the spindle.

According to the invention in said second method the correspondingchecking of the tool or workpiece spindles for damage or wear can beperformed solely by checking the measurement signal values within ashort time slot during the acceleration or deceleration of the spindleand, for this purpose, a correspondingly short monitoring stage can betransmitted to the monitoring device.

According to the invention in a third method for theprocess-accompanying monitoring of machine tool components by use of theabove described monitoring system according for the monitoring ofinadmissible imbalance on drilling or workpiece spindles or on drillingor milling tools, the tool or workpiece spindles are provided,preferably on the spindle housing near the bearings, with vibrationsensors for the detection of spindle or workpiece vibrations, or withdistance sensors for the detection of displacements between two spindlecomponents, preferably between rotor and stator relative to each other,further with sensors for generating one pulse per spindle revolutionwhich makes it possible for the monitoring system 10 to read only themaximum values of the vibration signal within each spindle revolutionfor purposes of comparison to the threshold values, or to eliminatedisturbing vibrations from the vibration or distance signals by means ofa pulse- or rotational-speed-dependent notch filter.

According to the invention in said third method the machine control 16during the time in which it sets the monitoring system 10 to themonitoring stage for the checking of tool or workpiece spindles forimbalance, can control also the spindles into the rotational speedranges to be monitored, while these do not carry tools or workpieces atthis time, and can perform the controlling of the spindles through an NCsubprogram portion which is called up together with the data word forthe monitoring stage.

Further according to the invention in said third method, during thecalling-up of the respective monitoring stages for the checking of toolor workpiece spindles for imbalance, the respective rotational speedscan be always identical, and the respective monitoring cycles for thecorresponding tool or workpiece spindles can be repeatedly initiated bythe machine control 16 at regular time intervals.

Further in said third method the monitoring stages for the well-aimedchecking of tool or workpiece spindles for imbalance can be preset bythe machine control 16 virtually for an unlimited number of times duringthe lifespan of a machine tool.

Further the distance in time between respectively two identicalmonitoring stages for the well-aimed checking of tool or workpiecespindles for imbalance can be preset by the machine control 16 inaccordance to the time when a just about perceptible imbalance-inducedchange on the tool or workpiece spindles would be expected.

According to the invention in said third method in new orunobjectionably balanced tool or workpiece spindles, respectively oneteach-in monitoring stage can be performed in which the measurementsignals 102 of the sensors 11, 12, 13 are stored in the monitoringsystem 10 and, in relation thereto, the switching thresholds for themaximum allowable deviations of the sensor signals for the futuremonitoring stages are determined up to the point when an inadmissibleimbalance of the tool or workpiece spindles is reached.

Further according to the invention in said third method the measurementsignals of the sensors from the sequential identical monitoring stagesfor the monitoring of imbalance of the tool or workpiece spindles can bestored in the monitoring system 10 and be read out at all times.

Further in said third method, particularly in the mass production ofworkpieces, the machine control 16, in order to check drilling andmilling tools for inadmissible imbalance, can be perform the normal NCprogram for treatment of this workpiece but will additionally transmitto the monitoring system 10 respectively one workpiece-specificmonitoring stage for checking the respective drilling and milling toolsfor inadmissible imbalance during the respective acceleration of thetool spindle with the respective tool to the respective desiredrotational speed.

Further the corresponding checking of the workpiece spindles forinadmissible imbalance of the respective drilling and milling tools canbe performed only by checking the measurement signal values within ashort time slot during the acceleration of the spindle and, for thispurpose, a correspondingly short monitoring stage can be transmittedfrom the machine control 16 to the monitoring device and this monitoringstage can be preferably transmitted at about 50% of the desiredrotational number so that a further acceleration in a condition ofundesired imbalance of the workpiece spindles with the respectivedrilling or milling tool can be avoided by direct switch-off of thespindle.

Further in new or unobjectionably balanced tool spindles and respectivedummy tools with defined, just about tolerable imbalances instead of theoriginal tools in the tool spindles, there can be performed respectivelyonce a teach-in monitoring stage for all tool types wherein themeasurement signals 102 of the sensors 11, 12, 13 are stored in themonitoring system 10 and, in correspondence thereto, the switchingthresholds for the maximum allowable deviations of the sensor signalsfor the future monitoring stages are determined up to the point when aninadmissible imbalance of the drilling or milling is reached.

According to the invention the above described monitoring system, forthe monitoring of damage or wear on other engine-driven devices of themachine, such as an hydraulic aggregate, a cooling lubricant pump, drivemeans for the protective door etc., to be referred to as aggregateshereunder, said engine-driven devices of the machine can be providedwith current or performance sensors on the drive engines, or, for themonitoring of noises or vibrations on the aggregates, can be providedwith one or a plurality of sensors for structure-borne noise and/or withvibration sensors.

According to the invention in a fourth method for process-accompanyingmonitoring of machine tool components by use of the latter monitoringsystem 10 the machine control 16 during the time in which it sets themonitoring system to the monitoring stage for the checking ofaggregates, can operate or reciprocate also the corresponding aggregatesthrough the performance ranges to be monitored, preferably through thecomplete performance ranges, while not carrying out a treatment processat this time, and can perform these movements through an NC subprogramportion which is called up together with the data word for themonitoring stage.

According to the invention in said fourth method the machine control canperform the monitoring stage for the monitoring of aggregates when noworkpiece is arranged in the machine so that the aggregates can beoperated or reciprocated throughout their performance range without adanger of collision and without a treatment process.

Further in said fourth method the monitoring stage for the well-aimedmonitoring of aggregates can be preset by the machine control 16virtually for an unlimited number of times during the lifespan of amachine tool.

Further the distance in time between respectively two identicalmonitoring stages for the well-aimed checking of aggregates can bepreset by the machine control 16 in accordance to the time when a justabout perceptible wear-induced change on the aggregates would beexpected.

According to the invention in said fourth method in new orunobjectionable, wear-free aggregates, a teach-in monitoring stage canbe performed in which the measurement signals 102 or measurement signalcurves of the sensors 11, 12, 13 are stored in the monitoring system 10and, in relation thereto, the switching thresholds or switchingthreshold curves for the maximum allowable deviations of the sensorsignals for the future monitoring stages are determined up to the end ofthe lifespan of the aggregates.

Further in said fourth method the measurement signals or measurementsignal curves of the sensors from the sequential identical monitoringstages for the monitoring of the aggregates can be stored in themonitoring system 10 and be read out at all times.

Although a preferred embodiment of the invention has been specificallydescribed herein, it is to be understood that minor variations may bemade in the invention without departing from the spirit and scopethereof, as defined by the appended claims.

1. A monitoring system for the process-accompanying monitoring of tools,workpieces or treatment processes in machine tools of the cutting typefor rotating, drilling or milling, with the purpose of detecting atleast one of the conditions of tool breakage, tool breakout, tool wear,contact between tool and workpiece with or without workpiece gauging,machine collision or process abnormities such as rattling, or tool-,workpiece- or cut-specific overload or underload, comprising at leastone or a plurality of sensors for the detection of measuring signalsfrom the treatment process, which are representative of at least adirection of force, a resultant force, a pressure, a moment of rotation,an engine performance, an engine current, a vibration, an acceleration,a structure-born sound or a change of distance between two machinecomponents, monitoring hardware with software for the storing andcomparing of monitoring data in tool- or cut-specific monitoring stageswhich are preset by the machine control means through the NC or/and SPCprogram via an interface and in which measurement signals or measurementsignal curves of at least one sensor are compared with stored monitoringthresholds by means of monitoring and evaluation strategies of a knownand desired type such as static thresholds, dynamic thresholds,thresholds of signal pattern curves, operating value thresholds, etc.with the purpose of providing, in case of measurement signals violatingthe monitoring thresholds, a corresponding message to the machinecontrol means to thus initiate a corresponding reaction of the machine,a bidirectional interface, preferably a field bus interface between themonitoring hardware and the machine control means, comprising the SPCor/and the NC control means, which performs a data exchange between themachine and the monitoring system and which particularly is suited totransmit the tool- or cut-specific monitoring stages in the form of datawords as distinct numbers or instructions (e.g. as tool codes, toolcorrection or position numbers, cutting code, H and M instructions),from the NC or SPC program to the monitoring system for dividing themonitoring into a plurality of monitoring stages, as well as, possiblyoptionally, operating hardware for operating and/or parametrizing themonitoring system and/or for visualizing the measurement signals,characterized in that the same monitoring system, apart from thedetection of at least one of the above mentioned conditions in tools,workpieces or processes, is used in other monitoring stages, which attimes when no treatment process occurs (i.e. when no tool, workpiece orprocess monitoring has to occur) are predetermined by the machinecontrol, to perform a detection, monitoring or well-aimed examination offaulty conditions on components of machine tools, such as e.g. damage orwear on the feed slides, on the tool or workpiece spindles or theimbalance on tool or workpiece spindles or on drilling or milling tools.2. The monitoring system according to claim 1, characterized in that themonitoring system can comprise, for each monitoring task to be performedon components of machine tools, one or a plurality of additional sensorssuited to this task which automatically switch the monitoring systemwhen the corresponding monitoring stage for the monitoring task to beperformed on components of machine tools is called up by the machinecontrol.
 3. The monitoring system according to claim 2, characterized inthat, for the monitoring of damage or wear on feed slides, these areprovided with force sensors for detecting the feed force in the slidemoving direction on one of the feed spindle bearing blocks, or areprovided with current or performance sensors on the feed spindleengines, or, by reading the measurement values of the existing currentsensors on the feed drive means from the machine control means, via thebidirectional interface, which is preferably designed as a field businterface, or, for a possible monitoring of noises or vibrations on feedslides, these are provided with one or a plurality of sensors forstructure-borne noise and/or vibration sensors arranged on the slides,the moving tracks or/and the spindle bearing blocks.
 4. A method for theprocess-accompanying monitoring of machine tool components by use of amonitoring system according to claim 2, characterized in that, for themonitoring of damage or wear on tool or workpiece spindles, primarily ontheir bearings, as well as for the examination of inadmissible imbalanceon tool or workpiece spindles, these are provided with sensors forstructure-borne sound provided for the detection of the running noise,or with vibration sensors for the detection of spindle vibrations, orwith distance sensors for the detection of displacements between twospindle components, preferably between rotor and stator relative to eachother, or with temperature sensors for the detection ofpower-loss-induced increases in temperature, which are each arranged inthe immediate region of the bearings, or with current or performancesensors on the tool or workpiece engine, further, by reading out themeasurement values of the existing current sensors on the spindle drivemeans from the machine control, via the bidirectional interface, whichis preferably provided as a field bus interface, for the detection ofpower-loss-induced increases in current or performance.
 5. A method forthe process-accompanying monitoring of machine tool components by use ofa monitoring system according to claim 2, characterized in that, for themonitoring of inadmissible imbalance on drilling or workpiece spindlesor on drilling or milling tools, the tool or workpiece spindles areprovided, preferably on the spindle housing near the bearings, withvibration sensors for the detection of spindle or workpiece vibrations,or with distance sensors for the detection of displacements between twospindle components, preferably between rotor and stator relative to eachother, further with sensors for generating one pulse per spindlerevolution which makes it possible for the monitoring system to readonly the maximum values of the vibration signal within each spindlerevolution for purposes of comparison to the threshold values, or toeliminate disturbing vibrations from the vibration or distance signalsby means of a pulse- or rotational-speed-dependent notch filter.
 6. Themonitoring system according to claim 2, characterized in that, for themonitoring of damage or wear on other engine-driven devices of themachine, such as an hydraulic aggregate, a cooling lubricant pump, drivemeans for the protective door etc., to be referred to as aggregateshereunder, these are provided with current or performance sensors on thedrive engines, or, for the monitoring of noises or vibrations on theaggregates, these are provided with one or a plurality of sensors forstructure-borne noise and/or with vibration sensors.
 7. The monitoringsystem according to claim 1, characterized in that, for the monitoringof damage or wear on feed slides, these are provided with force sensorsfor detecting the feed force in the slide moving direction on one of thefeed spindle bearing blocks, or are provided with current or performancesensors on the feed spindle engines, or, by reading the measurementvalues of the existing current sensors on the feed drive means from themachine control means, via the bidirectional interface, which ispreferably designed as a field bus interface, or, for a possiblemonitoring of noises or vibrations on feed slides, these are providedwith one or a plurality of sensors for structure-borne noise and/orvibration sensors arranged on the slides, the moving tracks or/and thespindle bearing blocks.
 8. A method for the process-accompanyingmonitoring of machine tool components by use of a monitoring systemaccording claim 1, characterized in that the machine control, during theperiod in which it sets the monitoring system to enter the monitoringstate for the monitoring of feed slides, will also move the one or theplurality of feed slides across the moving regions to be monitored,preferably across the complete moving regions without performing atreatment process at this time, and that the machine control can carryout these movements through an NC subprogram portion which is called uptogether with the data word for the monitoring stage.
 9. The methodaccording to claim 8, characterized in that the machine control performsthe monitoring stage for the monitoring of feed slides when no workpieceis arranged in the machine so that the complete moving regions can bemoved or reciprocated without a danger of collision and without atreatment process.
 10. The method according to claim 8, characterized inthat, particularly in the mass production of workpieces, the machinecontrol, for the monitoring stage for the monitoring of feed slides,will cause its feed slides to perform the normal NC program fortreatment of this workpiece but will not insert a workpiece into themachine for this purpose and in this case, instead of the monitoringstages for the monitoring of tools, workpieces or treatment processes,will transmit the monitoring stage for the monitoring of feed slides tothe monitoring system.
 11. The method according to claim 8,characterized in that, during the call-up of the monitoring stage, themovement of the feed slide is always identical and the monitoring cycleis repeatedly initiated by the machine control at regular time intervalsand with identical operating conditions.
 12. The method according toclaim 8, characterized in that the monitoring stage for the well-aimedmonitoring of feed slides can be preset by the machine control virtuallyfor an unlimited number of times during the lifespan of the machinetool.
 13. The method according to claim 12, characterized in that thedistance in time between respectively two identical monitoring stagesfor the well-aimed monitoring of feed slides is preset by the machinecontrol in accordance to the time when a just about perceptiblewear-induced change on the moving tracks would be expected.
 14. Themethod according to claim 8, characterized in that in new orunobjectionable, wear-free feed slides, a teach-in monitoring stage isperformed in which the measurement signals or measurement signal curvesof the sensors are stored in the monitoring system and, in relationthereto, the switching thresholds or switching threshold curves for themaximum allowable deviations of the sensor signals for the futuremonitoring stages are determined up to the end of the lifespan of thefeed slides of the machine tool.
 15. The method according to claim 8,characterized in that the measurement signals or measurement signalcurves of the sensors from the sequential identical monitoring stagesfor the monitoring of the feed slides can be stored in the monitoringsystem and be read out at all times.
 16. The method according to claim8, characterized in that, after machine collision or tool breakage,which the machine control can detect as a matter of a standard featureand which it will communicate to the machine control, the machinecontrol, after elimination of the collision or breakage situation, willfirst perform, at the start of the regular treatment in automaticoperation, a—relatively to the otherwise common chronologicalorder—unscheduled monitoring stage for the well-aimed monitoring of thefeed slides, and that the monitoring system will in this case separatelystore the measurement signals or measurement signal curves of thesensors in order to document possible damage caused by the collision orthe tool breakage on the feed slides.
 17. A method for theprocess-accompanying monitoring of machine tool components by use of amonitoring system according to claim 1, characterized in that, for themonitoring of damage or wear on tool or workpiece spindles, primarily ontheir bearings, as well as for the examination of inadmissible imbalanceon tool or workpiece spindles, these are provided with sensors forstructure-borne sound provided for the detection of the running noise,or with vibration sensors for the detection of spindle vibrations, orwith distance sensors for the detection of displacements between twospindle components, preferably between rotor and stator relative to eachother, or with temperature sensors for the detection ofpower-loss-induced increases in temperature, which are each arranged inthe immediate region of the bearings, or with current or performancesensors on the tool or workpiece engine, further, by reading out themeasurement values of the existing current sensors on the spindle drivemeans from the machine control, via the bidirectional interface, whichis preferably provided as a field bus interface, for the detection ofpower-loss-induced increases in current or performance.
 18. The methodaccording to claim 17, characterized in that the machine control duringthe time in which it sets the monitoring system to the monitoring stagefor the monitoring of tool or workpiece spindles, will control also thespindles into the rotational speed ranges to be monitored, andpreferably will increase and decrease their rotation through their wholerotational speed range without performing a treatment process at thistime, and can perform the controlling of the spindles through an NCsubprogram portion which is called up together with the data word forthe monitoring stage.
 19. The method according to claim 18,characterized in that the machine control performs the monitoring stagefor the monitoring of tool spindles when no tool is arranged in themachine so that the measurement signals cannot be adulterated by thetool.
 20. The method according to claim 18, characterized in that themachine control means performs the monitoring stage for the monitoringof workpiece spindles when no tool is arranged in the machine and theworkpiece chuck is positioned identically so that the measurementsignals cannot be adulterated by the workpiece or the workpiece chuck.21. The method according to claim 18, characterized in that,particularly in the mass production of workpieces, the machine control,for checking the tool or workpiece spindles for damage or wear, willperform the normal NC program for treatment of this workpiece but willtransmit to the monitoring system, in addition to the normal monitoringcycles for the monitoring of tools, workpieces or treatment processes, aspecific monitoring stage for checking the tool or workpiece spindlesfor damage or wear during the respective acceleration of the spindle tothe respective desired rotational speed prior to the treatment processinvolving the respective tool or workpiece, and in the process willcheck the measurement signals in the acceleration phase of the spindlepreferably by expansion of signal pattern curves from a correspondingteach-in monitoring stage.
 22. The method according to claim 17,characterized in that the machine control performs the monitoring stagefor the monitoring of tool spindles when no tool is arranged in themachine so that the measurement signals cannot be adulterated by thetool.
 23. The method according to claim 17, characterized in that themachine control means performs the monitoring stage for the monitoringof workpiece spindles when no tool is arranged in the machine and theworkpiece chuck is positioned identically so that the measurementsignals cannot be adulterated by the workpiece or the workpiece chuck.24. The method according to claim 17, characterized in that, during thecalling-up of the respective monitoring stages for the monitoring of thetool or workpiece spindles, the respective developments of therotational speeds inclusive of the acceleration or deceleration phasesare always identical, and that the respective monitoring cycles for thecorresponding tool or workpiece spindles are repeatedly initiated by themachine control with identical operating conditions of the machine tool.25. The method according to any claim 17, characterized in that themonitoring stages for the well-aimed monitoring of tool or workpiecespindles can be preset by the machine control virtually for an unlimitednumber of times during the lifespan of a machine tool.
 26. The methodaccording to claim 25, characterized in that the distance in timebetween respectively two identical monitoring stages for the well-aimedmonitoring of feed slides is preset by the machine control in accordanceto the time when a just about perceptible wear-induced change on themoving tracks would be expected.
 27. The method according to claim 17,characterized in that in new or unobjectionable, wear-free tool orworkpiece spindles, respectively one teach-in monitoring stage isperformed in which the measurement signals or measurement signal curvesof the sensors are stored in the monitoring system and, in relationthereto, the switching thresholds or switching threshold curves for themaximum allowable deviations of the sensor signals for the futuremonitoring stages are determined up to the end of the lifespan of thetool or workpiece spindles in the machine tool.
 28. The method accordingto claim 17, characterized in that the measurement signals ormeasurement signal curves of the sensors from the sequential identicalmonitoring stages for the monitoring of the tool or workpiece spindles,can be stored in the monitoring system and be read out at all times. 29.The method according to claim 17, characterized in that, after machinecollision or tool breakage, which the machine control can detect as amatter of a standard feature and which it communicates to the machinecontrol, the machine control, after elimination of the collision orbreakage situation, will first perform, at the start of the regulartreatment in automatic operation, a—relatively to the otherwise commonchronological order—unscheduled monitoring stage for the well-aimedmonitoring of the tool or workpiece spindles, and that the monitoringsystem will in this case separately store the measurement signals ormeasurement signal curves of the sensors in order to document possibledamage caused by the collision or the tool breakage on the tool orworkpiece spindles.
 30. The method according to claim 17, characterizedin that, particularly in the mass production of workpieces, the machinecontrol, for checking the tool or workpiece spindles for damage or wear,will perform the normal NC program for treatment of this workpiece butwill transmit to the monitoring system, in addition to the normalmonitoring cycles for the monitoring of tools, workpieces or treatmentprocesses, a specific monitoring stage for checking the tool orworkpiece spindles for damage or wear during the respective accelerationof the spindle to the respective desired rotational speed prior to thetreatment process involving the respective tool or workpiece, and in theprocess will check the measurement signals in the acceleration phase ofthe spindle preferably by expansion of signal pattern curves from acorresponding teach-in monitoring stage.
 31. The method according toclaim 30, characterized in that the corresponding checking can beperformed during the deceleration of the spindle.
 32. The methodaccording to claim 31, characterized in that the corresponding checkingof the tool or workpiece spindles for damage or wear is performed solelyby checking the measurement signal values within a short time slotduring the acceleration or deceleration of the spindle and that, forthis purpose, a correspondingly short monitoring stage is transmitted tothe monitoring device.
 33. The method according to claim 30,characterized in that the corresponding checking of the tool orworkpiece spindles for damage or wear is performed solely by checkingthe measurement signal values within a short time slot during theacceleration or deceleration of the spindle and that, for this purpose,a correspondingly short monitoring stage is transmitted to themonitoring device.
 34. A method for the process-accompanying monitoringof machine tool components by use of a monitoring system according toclaim 1, characterized in that, for the monitoring of inadmissibleimbalance on drilling or workpiece spindles or on drilling or millingtools, the tool or workpiece spindles are provided, preferably on thespindle housing near the bearings, with vibration sensors for thedetection of spindle or workpiece vibrations, or with distance sensorsfor the detection of displacements between two spindle components,preferably between rotor and stator relative to each other, further withsensors for generating one pulse per spindle revolution which makes itpossible for the monitoring system to read only the maximum values ofthe vibration signal within each spindle revolution for purposes ofcomparison to the threshold values, or to eliminate disturbingvibrations from the vibration or distance signals by means of a pulse-or rotational-speed-dependent notch filter.
 35. The method according toclaim 34, characterized in that the machine control during the time inwhich it sets the monitoring system to the monitoring stage for thechecking of tool or workpiece spindles for imbalance, will control alsothe spindles into the rotational speed ranges to be monitored, whilethese do not carry tools or workpieces at this time, and can perform thecontrolling of the spindles through an NC subprogram portion which iscalled up together with the data word for the monitoring stage.
 36. Themethod according to claim 35, characterized in that, during thecalling-up of the respective monitoring stages for the checking of toolor workpiece spindles for imbalance, the respective rotational speedsare always identical, and that the respective monitoring cycles for thecorresponding tool or workpiece spindles can be repeatedly initiated bythe machine control at regular time intervals.
 37. The method accordingto claim 35, characterized in that, particularly in the mass productionof workpieces, the machine control, in order to check drilling andmilling tools for inadmissible imbalance, will perform the normal NCprogram for treatment of this workpiece but will additionally transmitto the monitoring system respectively one workpiece-specific monitoringstage for checking the respective drilling and milling tools forinadmissible imbalance during the respective acceleration of the toolspindle with the respective tool to the respective desired rotationalspeed.
 38. The method according to claim 34, characterized in that,during the calling-up of the respective monitoring stages for thechecking of tool or workpiece spindles for imbalance, the respectiverotational speeds are always identical, and that the respectivemonitoring cycles for the corresponding tool or workpiece spindles canbe repeatedly initiated by the machine control at regular timeintervals.
 39. The method according to claim 34, characterized in thatthe monitoring stages for the well-aimed checking of tool or workpiecespindles for imbalance can be preset by the machine control virtuallyfor an unlimited number of times during the lifespan of a machine tool.40. The method according to claim 39, characterized in that the distancein time between respectively two identical monitoring stages for thewell-aimed checking of tool or workpiece spindles for imbalance ispreset by the machine control in accordance to the time when a justabout perceptible imbalance-induced change on the tool or workpiecespindles would be expected.
 41. The method according to claim 34,characterized in that in new or unobjectionably balanced tool orworkpiece spindles, respectively one teach-in monitoring stage isperformed in which the measurement signals of the sensors are stored inthe monitoring system and, in relation thereto, the switching thresholdsfor the maximum allowable deviations of the sensor signals for thefuture monitoring stages are determined up to the point when aninadmissible imbalance of the tool or workpiece spindles is reached. 42.The method according to claim 34, characterized in that the measurementsignals of the sensors from the sequential identical monitoring stagesfor the monitoring of imbalance of the tool or workpiece spindles can bestored in the monitoring system and be read out at all times.
 43. Themethod according to claim 34, characterized in that, particularly in themass production of workpieces, the machine control, in order to checkdrilling and milling tools for inadmissible imbalance, will perform thenormal NC program for treatment of this workpiece but will additionallytransmit to the monitoring system respectively one workpiece-specificmonitoring stage for checking the respective drilling and milling toolsfor inadmissible imbalance during the respective acceleration of thetool spindle with the respective tool to the respective desiredrotational speed.
 44. The method according to claim 43, characterized inthat the corresponding checking of the workpiece spindles forinadmissible imbalance of the respective drilling and milling tools isperformed only by checking the measurement signal values within a shorttime slot during the acceleration of the spindle and that, for thispurpose, a correspondingly short monitoring stage is transmitted fromthe machine control to the monitoring device and that this monitoringstage is preferably transmitted at about 50% of the desired rotationalnumber so that a further acceleration in a condition of undesiredimbalance of the workpiece spindles with the respective drilling ormilling tool can be avoided by direct switch-off of the spindle.
 45. Themethod according to claim 44, characterized in that in new orunobjectionably balanced tool spindles and respective dummy tools withdefined, just about tolerable imbalances instead of the original toolsin the tool spindles, there is performed respectively once a teach-inmonitoring stage for all tool types wherein the measurement signals ofthe sensors are stored in the monitoring system and, in correspondencethereto, the switching thresholds for the maximum allowable deviationsof the sensor signals for the future monitoring stages are determined upto the point when an inadmissible imbalance of the drilling or millingis reached.
 46. The method according to claim 43, characterized in thatin new or unobjectionably balanced tool spindles and respective dummytools with defined, just about tolerable imbalances instead of theoriginal tools in the tool spindles, there is performed respectivelyonce a teach-in monitoring stage for all tool types wherein themeasurement signals of the sensors are stored in the monitoring systemand, in correspondence thereto, the switching thresholds for the maximumallowable deviations of the sensor signals for the future monitoringstages are determined up to the point when an inadmissible imbalance ofthe drilling or milling is reached.
 47. The monitoring system accordingto claim 1, characterized in that, for the monitoring of damage or wearon other engine-driven devices of the machine, such as an hydraulicaggregate, a cooling lubricant pump, drive means for the protective dooretc., to be referred to as aggregates hereunder, these are provided withcurrent or performance sensors on the drive engines, or, for themonitoring of noises or vibrations on the aggregates, these are providedwith one or a plurality of sensors for structure-borne noise and/or withvibration sensors.
 48. A method for process-accompanying monitoring ofmachine tool components by use of a monitoring system according to claim47, characterized in that the machine control during the time in whichit sets the monitoring system to the monitoring stage for the checkingof aggregates, will operate or reciprocate also the correspondingaggregates through the performance ranges to be monitored, preferablythrough the complete performance ranges, while not carrying out atreatment process at this time, and can perform these movements throughan NC subprogram portion which is called up together with the data wordfor the monitoring stage.
 49. The method according to claim 47,characterized in that the machine control performs the monitoring stagefor the monitoring of aggregates when no workpiece is arranged in themachine so that the aggregates can be operated or reciprocatedthroughout their performance range without a danger of collision andwithout a treatment process.
 50. The method according to claim 47,characterized in that the monitoring stage for the well-aimed monitoringof aggregates can be preset by the machine control virtually for anunlimited number of times during the lifespan of a machine tool.
 51. Themethod according to claim 50, characterized in that the distance in timebetween respectively two identical monitoring stages for the well-aimedchecking of aggregates is preset by the machine control in accordance tothe time when a just about perceptible wear-induced change on theaggregates would be expected.
 52. The method according to claim 47,characterized in that in new or unobjectionable, wear-free aggregates, ateach-in monitoring stage is performed in which the measurement signalsor measurement signal curves of the sensors are stored in the monitoringsystem and, in relation thereto, the switching thresholds or switchingthreshold curves for the maximum allowable deviations of the sensorsignals for the future monitoring stages are determined up to the end ofthe lifespan of the aggregates.
 53. The method according to claim 47,characterized in that the measurement signals or measurement signalcurves of the sensors from the sequential identical monitoring stagesfor the monitoring of the aggregates can be stored in the monitoringsystem and be read out at all times.